JAKARTA, June 18 (Reuters) - Indonesia's promises to tackle the upcoming annual "haze" season with a $30 million fund and limited military equipment have been called into question by experts anticipating worse pollution levels than last year due to the El Nino weather pattern.

Indonesia has failed in previous attempts to stop the regional haze, with last year giving the worst pollution readings since 1997. Outgoing Indonesian President Susilo Bambang Yudhoyono was forced in mid-2013 to apologise to neighbours Singapore and Malaysia, which were blanketed in thick smog caused by forest fires in Indonesia.

With expectations high that the El Nino dry weather pattern will hit around the middle of the year, the haze could be worse than in 2013, conservation experts told Reuters.

"We are talking hundreds of thousands of hectares that will probably burn and I doubt (the government) will be able to cover this much of an area," said David Gaveau, a scientist at the Center for International Forestry Research, a conservation organisation based in Indonesia.

"We're expecting El Nino and if it comes, we're going to see much more fires than last year."

The heavy smoke from slash-and-burn clearances often comes from the islands of Sumatra and Kalimantan, where large forest concessions are used by pulp and paper and palm oil companies, some of which are listed in Singapore.

Both palm and pulp and paper companies, which blame small-holders for the fires, have been criticised by green groups for not doing enough to stop the haze or the rampant deforestation and destruction of carbon-rich peatlands in Indonesia.

"Anything to do with fighting the fire as it happens is fine, but this is not really going to tackle the problem of why there is a fire in the first place," Gaveau added. "The root problem is overlapping claims over land ownership."

As a sign of things to come, earlier this year Indonesia's Riau province off Sumatra island declared a state of emergency as haze from raging forest fires disrupted flights and marine navigation and tens of thousands fell sick with respiratory problems. The airport in the provincial capital closed for more than three weeks.

To prepare this year, Indonesia has put aside $30 million and will have 2,500 military personnel on standby, with 15 aeroplanes and helicopters helping with water-bombing, monitoring and cloud-seeding efforts, Sutopo Nugroho, spokesman at the Indonesian disaster management agency, told Reuters.

Singapore has also offered assistance in assessing and putting out forest fires in Indonesia and proposed a law to punish individuals and companies outside its borders that are responsible for polluting its air.

With presidential elections due to take place on July 9, Yudhoyono, who has reached his two-term limit, introduced a moratorium on forest clearing during his ten years in office and will be keen to maintain his environmental credentials.

"This year we have prepared the technology and ... local governments have also been asked to identify and arrest the perpetrators early," Coordinating Minister for People's Welfare Agung Laksono told Reuters. (Additional reporting by Dennys Kapa in Jakarta and Rujun Shen in Singapore; Editing by Nick Macfie)